From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A296FC1975A for ; Thu, 12 Mar 2020 22:35:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 765652072F for ; Thu, 12 Mar 2020 22:35:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584052552; bh=SfqP7PEMaKf+gRsPXn7apmeBBbzuIezfP5hhZsmY+hU=; h=Date:From:To:Subject:In-Reply-To:List-ID:From; b=hxu+VhrY7uHnkhfqEl8s1JCMp/eJcH//wG2ohTF4eE6iXloqLfHzgbU1Pgog6BRHL SL1UoAn0hqt9HwZXM08+lg2APvFcavRfoorPpwR/ys07eKUbXSOHr+PBaGRdq8lcUo zFRU8Sb6Frl0UKjKo/IBJf2tB6u6lR24oijgnmp4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726620AbgCLWfw (ORCPT ); Thu, 12 Mar 2020 18:35:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:53482 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726605AbgCLWfv (ORCPT ); Thu, 12 Mar 2020 18:35:51 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 127EF20637; Thu, 12 Mar 2020 22:35:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584052551; bh=SfqP7PEMaKf+gRsPXn7apmeBBbzuIezfP5hhZsmY+hU=; h=Date:From:To:Subject:In-Reply-To:From; b=RKQs2VugEHice05kzDYI/9udOzWQKjQ4MNbDU8VjC27BLdR66A2anhgKgPtZ7Bq9g k/EvdF3S/NJUOzzxVOr0CgN3z5NXhfXOgFhshSrMCVMe+kMW6/cI7GqZT2g/RB7BZB nMoE18ookwiQHryxF6UHen4zFv8zr896t4B81av8= Date: Thu, 12 Mar 2020 15:35:50 -0700 From: Andrew Morton To: chris@chrisdown.name, guro@fb.com, hannes@cmpxchg.org, mhocko@kernel.org, mm-commits@vger.kernel.org, natechancellor@gmail.com, stable@vger.kernel.org, tj@kernel.org Subject: + mm-memcg-fix-corruption-on-64-bit-divisor-in-memoryhigh-throttling.patch added to -mm tree Message-ID: <20200312223550.r2GLIpLEX%akpm@linux-foundation.org> In-Reply-To: <20200305222751.6d781a3f2802d79510941e4e@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch titled Subject: mm, memcg: fix corruption on 64-bit divisor in memory.high throttling has been added to the -mm tree. Its filename is mm-memcg-fix-corruption-on-64-bit-divisor-in-memoryhigh-throttling.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-memcg-fix-corruption-on-64-bit-divisor-in-memoryhigh-throttling.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-memcg-fix-corruption-on-64-bit-divisor-in-memoryhigh-throttling.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Chris Down Subject: mm, memcg: fix corruption on 64-bit divisor in memory.high throttling 0e4b01df8659 had a bunch of fixups to use the right division method. However, it seems that after all that it still wasn't right -- div_u64 takes a 32-bit divisor. The headroom is still large (2^32 pages), so on mundane systems you won't hit this, but this should definitely be fixed. Link: http://lkml.kernel.org/r/80780887060514967d414b3cd91f9a316a16ab98.1584036142.git.chris@chrisdown.name Fixes: 0e4b01df8659 ("mm, memcg: throttle allocators when failing reclaim over memory.high") Signed-off-by: Chris Down Reported-by: Johannes Weiner Cc: Tejun Heo Cc: Roman Gushchin Cc: Michal Hocko Cc: Nathan Chancellor Cc: [5.4.x+] Signed-off-by: Andrew Morton --- mm/memcontrol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/memcontrol.c~mm-memcg-fix-corruption-on-64-bit-divisor-in-memoryhigh-throttling +++ a/mm/memcontrol.c @@ -2350,7 +2350,7 @@ void mem_cgroup_handle_over_high(void) */ clamped_high = max(high, 1UL); - overage = div_u64((u64)(usage - high) << MEMCG_DELAY_PRECISION_SHIFT, + overage = div64_u64((u64)(usage - high) << MEMCG_DELAY_PRECISION_SHIFT, clamped_high); penalty_jiffies = ((u64)overage * overage * HZ) _ Patches currently in -mm which might be from chris@chrisdown.name are mm-memcg-fix-corruption-on-64-bit-divisor-in-memoryhigh-throttling.patch mm-memcg-throttle-allocators-based-on-ancestral-memoryhigh.patch